1. Field of the Invention
The present invention relates generally to a battery inspection system that is used to automatically inspect batteries such as lithium batteries using X-rays.
2. Description of the Prior Art
In general, lithium batteries can be fabricated to be relatively thin, and thus mounted on electronic apparatuses while occupying relatively small spaces, so the lithium batteries are widely employed for a variety of electronic apparatuses, such as imaging devices, communications equipments, optical instruments, medical instruments, computers, mobile phones and the like.
A general lithium battery is comprised of a square-shaped can made of metal, such as stainless steel, and a jelly roll wound in the form of a roll in the metallic can. After the jelly roll is placed in the metallic can and thereby the assembly of the lithium battery is completed, the lithium battery undergoes inspection for detecting manufacturing defects. The battery inspection system of the present invention is a system for inspecting lithium batteries for incorrect positioning of jelly rolls contained within metallic cans. In more detail, the battery inspection system of the present invention inspects the lithium batteries whether the winding of jelly rolls in metallic cans is corrected or not, the spacing between jelly rolls and metallic cans is maintained within an allowable error range or not, there is any infiltration of impurities into the metallic cans during assembly or not, or the like, using X-rays.
FIG. 1 is a plan view schematically showing a conventional battery inspection system. The conventional battery inspection system is comprised of a flat inspection table 1, a battery feeding conveyor 2, a circular feeding plate 3, a circular inspection plate 4, a circular discharging plate 5, a satisfactory battery discharging conveyor 6, a defective battery discharging conveyor 7, and a cam 8. The three circular plates 3, 4 and 5 and the cam 8 are rotatably positioned on the inspection table 1. The rear end of the battery feeding conveyor 2 is situated near the circular feeding plate 3, the front end of the satisfactory battery discharging conveyor 6 is situated near the circular discharging plate 5, and the front end of the defective battery discharging conveyor 7 is situated near the circular inspection plate 4.
A pair of bars 10 and 11 are attached to the cam 8 to be rotated by the rotation of the cam 8 within a predetermined range of angles.
Four battery accommodating members 12 are formed on the circular feeding plate 3, four battery accommodating members 12 are formed on the circular discharging plate 5, and eight battery accommodating members 12 are formed on the circular inspection plate 4. In order to arrange batteries B accommodated and moved in the battery accommodating members 12 at a precise inspection position or to move batteries B to the next circular plate or the conveyor, a plurality of cylinders 13 are positioned around the circular plates 3, 4 and 5. An X-ray generator 14 is situated under the circular inspection plate 4 to inspect batteries B.
In the inspection of batteries by the conventional battery inspection system, batteries B fed by the battery feeding conveyor 2 are removed to the battery accommodating members 12 by the cylinder 13 and, thereafter, the circular feeding plate 3 is rotated. At the same time, while the cam 8 is rotated, the bar 10 pushes the battery B positioned on the circular feeding plate 3 to the battery accommodating member 12 of the circular inspection plate 4. While the circular inspection plate 4 is sequentially rotated at regular intervals, the battery B removed to the circular inspection plate 3 is first arranged by the cylinder 13 to be situated at a first inspection position P1, and exposed to X-rays generated by the X-ray generator 14 to be inspected for defects at a position P2. Thereafter, the battery B is arranged at a second inspection position P2 by the cylinder 13, and another side of the battery B is inspected for defects. Subsequently, a satisfactory battery is removed to the circular discharging plate 5 by the cylinder 13, while a defective battery is further rotated at a predetermined angle and sent to the defective battery discharging conveyor 7 by the bar 11 attached to the cam 8. The satisfactory battery removed to the circular discharging plate 5 is sent to the satisfactory battery discharging conveyor 6 by the cylinder 13 and transferred to the next process.
With the repetition of the above-described process, the batteries fed through the battery feeding conveyor 2 are automatically inspected for defects.
However, in the conventional battery inspection system, since batteries are moved or arranged by a plurality of cylinders and bars, the jelly rolls may deviate from their correct positions by the shock of impacts exerted by the cylinders or bars in the process of inspecting jelly rolls and metallic cans for defects, thereby causing satisfactory batteries to become defective batteries.
In addition, in the conventional battery inspection system, its battery accommodating members are formed to accommodate only specifically sized batteries and the stroke lengths of its cylinders and bars are adjusted to remove the specifically sized batteries to the next process or arrange them at an appropriate inspection position. Hence, in order to inspect different models of differently sized batteries for defects, the size of the accommodating space of the battery accommodating members and the positions of the cylinders and the bars should be adjusted to fit the size of the differently sized batteries. As a result, excessive time is required to adjust the size of the accommodating space of the battery accommodating members and the positions of the cylinders and the bars to fit the size of the differently sized batteries, so the productivity of the batteries is deteriorated by the conventional battery inspection system.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a battery inspection system, which is capable of inspecting batteries for defects without causing the relative positions of their jelly rolls and metallic cans to be undesirably varied.
Another object of the present invention is to provide a battery inspection system, which is capable of being rapidly and conveniently adjusted for inspecting different models of type batteries.
In order to accomplish the above object, the present invention provides a battery inspection system, comprising: a battery feeding conveyor for feeding batteries to be inspected; one or more transfer robots positioned near the rear end of the battery feeding conveyor for transferring batteries fed through the battery feeding conveyor to inspection and discharge positions; an X-ray generator positioned under the transfer robots for applying X-rays to batteries transferred by the transfer robots; a satisfactory battery discharging conveyor positioned near the transfer robots for discharging satisfactory batteries moved by the transfer robots and having been inspected; and a defective battery discharging robot positioned near the front end of the satisfactory battery discharging conveyor for removing defective batteries from batteries moving along the satisfactory battery discharging conveyor and having been inspected.
The battery inspection system may further comprise a control unit for determining whether batteries are defective on the basis of X-ray images generated by the X-ray generator and controlling the defective battery discharging robot.
The control unit may comprise an image multiplier tube for multiplying X-ray images transmitted from the X-ray generator into visible ray images, a camera for photographing the images of the image multiplier tube, and a control panel for interpreting photographs taken by the camera and determining whether batteries are defective.
The battery inspection system may further comprise a defective battery discharging conveyor positioned near the front end of the satisfactory battery discharging conveyor for discharging defective batteries removed by the defective battery discharging robot.
The transfer robots may be comprised of a vertical transfer robot for simultaneously picking up batteries to be inspected and having been inspected and a horizontal transfer robot positioned under the vertical transfer robot for transferring batteries transferred by the vertical transfer robot to a precise inspection position, the X-ray generator may be positioned under the horizontal transfer robot, so that the vertical transfer robot simultaneously picks up batteries to be inspected and having been inspected from the battery feeding conveyor and the horizontal transfer robot, and transfers the batteries to the horizontal transfer robot and the satisfactory battery discharging conveyor, respectively, and the horizontal transfer robot positions batteries transferred by the vertical transfer robot right over the X-ray generator.
Preferably, The image multiplier tube and the camera are positioned over the horizontal transfer robot.
The battery inspection system may further comprise a battery separating conveyor positioned at the rear end of the battery feeding conveyor for separating a number of batteries equal in number to the number of batteries to be transferred by each of the transfer robots from the batteries fed through the battery feeding conveyor.